1.1.0-nullsafety.0 - Jan 18, 2021

• Migrate this package to null safety.
• Sdk constraints: >=2.12.0-0 <3.0.0 based on beta release guidelines.
• LoaderMessage.fold requires all arguments are not null.
• Dependencies:
  • Depends on rxdart_ext.
  • Removed built_value.